Let x is included with ratio of side.
hence two sides of the parallelogram are 3x, 5x.
As we know that opposite sides of parallelogram are equal.
so that four sides of this parallelogram are 3x, 5x, 3x and 5x, i.e length(l) = 5x and width(b) = 3x.
perimeter = 2(l+b) = 2(5x+3x).
perimeter = 48cm
or, 2(5x+3x) = 48
or, 8x =48/2
or, 8x =24
or, x =3
Therefore two sides are: length = 5x = 5×3 =15 cm and width = 3x = 3×3 = 9cm.